首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11351篇
  免费   112篇
  国内免费   2篇
管理学   1597篇
民族学   42篇
人才学   2篇
人口学   951篇
丛书文集   55篇
理论方法论   1027篇
综合类   154篇
社会学   5295篇
统计学   2342篇
  2023年   78篇
  2020年   173篇
  2019年   244篇
  2018年   233篇
  2017年   335篇
  2016年   255篇
  2015年   204篇
  2014年   245篇
  2013年   2002篇
  2012年   337篇
  2011年   283篇
  2010年   260篇
  2009年   241篇
  2008年   318篇
  2007年   320篇
  2006年   281篇
  2005年   259篇
  2004年   237篇
  2003年   228篇
  2002年   252篇
  2001年   238篇
  2000年   213篇
  1999年   208篇
  1998年   178篇
  1997年   186篇
  1996年   189篇
  1995年   149篇
  1994年   128篇
  1993年   165篇
  1992年   174篇
  1991年   165篇
  1990年   170篇
  1989年   142篇
  1988年   134篇
  1987年   143篇
  1986年   116篇
  1985年   109篇
  1984年   155篇
  1983年   134篇
  1982年   128篇
  1981年   108篇
  1980年   123篇
  1979年   125篇
  1978年   95篇
  1977年   109篇
  1976年   96篇
  1975年   100篇
  1974年   79篇
  1973年   75篇
  1972年   66篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
171.
By the mid-1980s, fertility in most of the world's developed countries had declined to unprecedentedly low levels. Since then, it has declined still further in some, increased slightly in others, and fluctuated in still others. Irrespective of cause, these changes could not have occurred in the absence of substantial control over childbearing.While future increases and decreases are both possible, it is argued that, contrary to the usual demographic expectations for populations exercising substantial control over fertility, fertility in most of these countries will increase to approximate replacement levels and then undergo only minor fluctuations around these levels thereafter.  相似文献   
172.
173.
从古希腊早期哲学家话语研究欧洲思想的起源是不够的,那是传统大树上的枝杈而非根脉。荷马史诗在某种程度上呈现出最早的希腊人的真实历史样貌,其中充满着后世文明人难以理解的野蛮因素。有关神话与传说的知识是重建文明发生过程的主要素材,是将石器时代与文明时代相连接的认知通道。《伊里亚特》《奥德赛》所透露的生活方式和思维方式像一座永久的历史记忆之丰碑,是我们现在所掌握的最早描写欧洲的生活和思想的活的教材。  相似文献   
174.
中国古代管理哲学与西方现代管理理论的差异和优劣势主要体现在管理的基本价值观、基本思维方式、管理主体和客体、主要目标、权力基础、基本管理方式以及管理创新特征等方面。双方相互借鉴的主要方向是:中国应借鉴西方保护个体利益并重视公平竞争和激励、追求标准化的科学管理、强调经济效益和效率、强调民主与“法治”、鼓励创新并保护创新成果等思想中的合理成分,以及西方在领导理论和工商管理领域的有益成果;西方应借鉴中国的人本论、整体观、系统观和权变观、“中庸之道”、“修己安人”、“和为贵”、世界“大同”、民本论、“道治”、“德治”和“智治”等管理思想中的合理成分,以及在伦理管理、国家管理和军事管理等领域的有益成果。  相似文献   
175.
Criminologists have long reported the existence of racial disparity in the criminal justice system, but the important question is why. While some argue that observed differences are a consequence of more criminal behavior among minorities, the weight of the evidence indicates that this is but a partial explanation. In this paper, we study data from a sample of juveniles to examine how racial differences in early police contact, and important social environments—family, school, and neighborhoods—affect later contact and arrests, controlling for self-reported delinquency. We find that early (in middle school) contact with police is an important predictor of later (high school) arrests. Also we found that, in addition to being male and living in a low-income family, children who have parents who have a history of arrest, who have experienced school disciplinary actions, who have delinquent peers, and who are in networks with deviant adults are more likely to have problems with law enforcement. These factors help to explain racial differences in police contacts and arrests.  相似文献   
176.
Interpretations and perceptions of the effects and content of rap music lyrics have been given considerable attention in the literature in recent years, yet few assessment tools have been developed that can produce reliable and valid inferences about these views. One exception is the Rap-music Attitude and Perception (RAP) Scale. This study examined the cross-racial effects on attitudes toward and perceptions of rap music using a sample of 1,254 college students. A cross-sectional survey design was used to gather these data. Three specific hypotheses were tested and were supported or partially supported. Alpha reliabilities for the full scale and for each of the three sub-scales were good for black and white students separately. Criterion validity for these groups was also good. Finally, tests of factorial equivalence suggested that the factor structure of the RAP was equivalent across racial groups. The RAP is a tool with strong psychometric properties and can be used by practitioners and researchers working with black and white subgroups. Directions for future research on the utility of the RAP are forwarded.  相似文献   
177.
The effect of bioaerosol size was incorporated into predictive dose‐response models for the effects of inhaled aerosols of Francisella tularensis (the causative agent of tularemia) on rhesus monkeys and guinea pigs with bioaerosol diameters ranging between 1.0 and 24 μm. Aerosol‐size‐dependent models were formulated as modification of the exponential and β‐Poisson dose‐response models and model parameters were estimated using maximum likelihood methods and multiple data sets of quantal dose‐response data for which aerosol sizes of inhaled doses were known. Analysis of F. tularensis dose‐response data was best fit by an exponential dose‐response model with a power function including the particle diameter size substituting for the rate parameter k scaling the applied dose. There were differences in the pathogen's aerosol‐size‐dependence equation and models that better represent the observed dose‐response results than the estimate derived from applying the model developed by the International Commission on Radiological Protection (ICRP, 1994) that relies on differential regional lung deposition for human particle exposure.  相似文献   
178.
The use of thimerosal preservative in childhood vaccines has been largely eliminated over the past decade in the United States because vaccines have been reformulated in single‐dose vials that do not require preservative. An exception is the inactivated influenza vaccines, which are formulated in both multidose vials requiring preservative and preservative‐free single‐dose vials. As part of an ongoing evaluation by USFDA of the safety of biologics throughout their lifecycle, the infant body burden of mercury following scheduled exposures to thimerosal preservative in inactivated influenza vaccines in the United States was estimated and compared to the infant body burden of mercury following daily exposures to dietary methylmercury at the reference dose established by the USEPA. Body burdens were estimated using kinetic parameters derived from experiments conducted in infant monkeys that were exposed episodically to thimerosal or MeHg at identical doses. We found that the body burden of mercury (AUC) in infants (including low birth weight) over the first 4.5 years of life following yearly exposures to thimerosal was two orders of magnitude lower than that estimated for exposures to the lowest regulatory threshold for MeHg over the same time period. In addition, peak body burdens of mercury following episodic exposures to thimerosal in this worst‐case analysis did not exceed the corresponding safe body burden of mercury from methylmercury at any time, even for low‐birth‐weight infants. Our pharmacokinetic analysis supports the acknowledged safety of thimerosal when used as a preservative at current levels in certain multidose infant vaccines in the United States.  相似文献   
179.
Security of infrastructure is a major concern. Traditional security schedules are unable to provide omnipresent coverage; consequently, adversaries can exploit predictable vulnerabilities to their advantage. Randomized security schedules, which randomly deploy security measures, overcome these limitations, but public perceptions of such schedules have not been examined. In this experiment, participants were asked to make a choice between attending a venue that employed a traditional (i.e., search everyone) or a random (i.e., a probability of being searched) security schedule. The absolute probability of detecting contraband was manipulated (i.e., 1/10, 1/4, 1/2) but equivalent between the two schedule types. In general, participants were indifferent to either security schedule, regardless of the probability of detection. The randomized schedule was deemed more convenient, but the traditional schedule was considered fairer and safer. There were no differences between traditional and random schedule in terms of perceived effectiveness or deterrence. Policy implications for the implementation and utilization of randomized schedules are discussed.  相似文献   
180.
Several colorectal cancer (CRC) screening models have been developed describing the progression of adenomas to CRC. Currently, there is increasing evidence that serrated lesions can also develop into CRC. It is not clear whether screening tests have the same test characteristics for serrated lesions as for adenomas, but lower sensitivities have been suggested. Models that ignore this type of colorectal lesions may provide overly optimistic predictions of the screen‐induced reduction in CRC incidence. To address this issue, we have developed the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model that includes the adenoma‐carcinoma pathway and the serrated pathway to CRC as well as characteristics of colorectal lesions. The model structure and the calibration procedure are described in detail. Calibration resulted in 19 parameter sets for the adenoma‐carcinoma pathway and 13 for the serrated pathway that match the age‐ and sex‐specific adenoma and serrated lesion prevalence in the COlonoscopy versus COlonography Screening (COCOS) trial, Dutch CRC incidence and mortality rates, and a number of other intermediate outcomes concerning characteristics of colorectal lesions. As an example, we simulated outcomes for a biennial fecal immunochemical test screening program and a hypothetical one‐time colonoscopy screening program. Inclusion of the serrated pathway influenced the predicted effectiveness of screening when serrated lesions are associated with lower screening test sensitivity or when they are not removed. To our knowledge, this is the first model that explicitly includes the serrated pathway and characteristics of colorectal lesions. It is suitable for the evaluation of the (cost)effectiveness of potential screening strategies for CRC.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号